Brake Proportioning Valve - Date Coded ??

[John S.]

As I continue to clean up and document everything I can on my '73, I've come across and interesting one. Not sure if this has been documented or not. From the attached photos and the "73 AIM, I've come up with the following:

Brake Proportioning Valve
Part Number 3980797
Patent Numbers 3369090 and 3374322

And what I believe could be a date code of 2-227 (Aug, 14th, 1972 ) ??

This falls in line with several other Julian date codes I have found plus it would be legit for my Dec 13th 1972 car.



Has anyone else documented or seen this before ??

[Joe L.]

Re: Brake Proportioning Valve - Date Coded ??

As I continue to clean up and document everything I can on my '73, I've come across and interesting one. Not sure if this has been documented or not. From the attached photos and the "73 AIM, I've come up with the following:

Brake Proportioning Valve
Part Number 3980797
Patent Numbers 3369090 and 3374322

And what I believe could be a date code of 2-227 (Aug, 14th, 1972 ) ??

This falls in line with several other Julian date codes I have found plus it would be legit for my Dec 13th 1972 car.



Has anyone else documented or seen this before ??

John------


This is not a proportioning valve although it's often incorrectly referred to as such. This part is called a "brake fluid distribution block and brake warning light switch". It has no proportioning function, at all. The only Corvettes that ever had a true proportioning valve were 1966-68 with J-56.
1978-82 had a COMBINATION valve which included brake fluid distribution, warning light, and fixed-rate proportioning functions.

[John S.]

Re: Brake Proportioning Valve - Date Coded ??

Joe - thanks for the update on the description. Any thoughts on the possible date code ??

John

[Mike E.]

Re: Brake Proportioning Valve - Date Coded ??

This dating is included in the upcoming 70-72 JG. You have decoded it correctly--it is a Julian date.

[Alan S.]

Re: Brake Proportioning Valve - Date Coded ??

Hi John,
I wonder if we're going to begin looking for re-stamps and the block's surface finish?
Regards,
Alan

[John S.]

Re: Brake Proportioning Valve - Date Coded ??

Alan, probably......... With every noted stamping there is certainly a chance for restamp. I note your surface finish has the same radial lines as mine does. My stamping does appear to be a double hit. There's a faint 2-227 behind the visible one. Thanks for the pic and your reply.

Also thanks to Mike for the date code reply. We'll have to add that one to our list of '73-'74 JG updates.